Novel agents for the treatment of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world. Currently, the most effective treatment for CLL consists of a combination of fludarabine, cyclophosphamide, and rituximab. Although this approach has encouraging results, patients with CLL eventually relapse and require additional therapies. Many of the current therapeutic regimens for CLL are myelotoxic, immunosuppressive, and associated with infectious complications. Targeted therapies can often minimize these complications. The US Food and Drug Administration has recently approved 2 agents, bendamustine and ofatumumab, for the treatment of CLL. Emerging therapies ranging from new monoclonal antibodies to small molecules that interfere with vital pathways in signal transduction and cell cycle regulation are currently being developed. This article will focus on novel agents in earlier development phases for CLL, including the immunomodulator lenalidomide; monoclonal antibodies, such as lumiliximab, GA-101, and small molecule immunopharmaceuticals; BCL-2 inhibitors, such as oblimersen, obatoclax, and ABT-263; and protein kinase inhibitors, such as flavopiridol, spleen tyrosine kinase inhibitors, and phosphatidylinositol 3-kinase inhibitors.